JPH0812877A - Flame retardant resin composition excellent in stability - Google Patents

Abstract

PURPOSE:To obtain the subject composition, comprising a polyphenylene ether resin, a specific phosphoric ester compound and a metallic oxide in a specified proportion without volatilizing, smoking and bleeding a flame retardant in molding processing, capable of withstanding the long-term use or recycling use and useful for electrical appliances, etc. CONSTITUTION:This composition comprises (A) 100 pts.wt. polyphenylene ether resin such as poly(2,6-dimethyl-1,4-phenylene)ether, preferably 100 pts.wt. total amount of 10-99 pts.wt. polyphenylene ether resin and 90-1 pts.wt. PS-based resin, (B) 0.1-30 pts.wt. phosphoric ester compound of the formula [R1 and R2 are each methyl; R3 and R4 are each H or methyl; (n) is >=1; n1 and n2 are each 0-2], (C) 0.01-7 pts.wt. metallic oxide such as zinc oxide or magnesium oxide and further (D) 0.01-7 pts.wt. metallic sulfide such as zinc sulfide.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flame-retardant resin composition having excellent stability, which comprises a polyphenylene ether resin composition, a specific phosphoric acid ester compound and a metal oxide. The flame-retardant resin composition of the present invention is free from volatilization, fuming and bleeding of the flame retardant during molding and has excellent stability to withstand long-term use and recycle use.

[0002]

2. Description of the Related Art Polyphenylene ether resins are excellent in mechanical properties, electrical properties, acid resistance, alkali resistance, heat resistance, etc., and have low water absorption and good dimensional stability. It is widely used as a material for housings and chassis of office automation equipment such as machines and word processors, but due to safety issues, these materials are often required to have high flame retardancy. Although polyphenylene ether resin has excellent flame retardancy, it is generally used as an alloy with a styrene resin because it is inferior in processability, but flame retardancy is impaired.

For the purpose of improving the flame retardancy of polyphenylene ether resins, it has been conventionally known to blend a phosphate ester compound such as triphenyl phosphate, cresyl diphenyl phosphate, tricresyl phosphate and isopropylphenyl phosphate as a flame retardant. ing. However, there are drawbacks such as deterioration of heat resistance and physical properties of the resin composition, volatilization of the phosphoric acid ester compound at the time of molding, smoking, bleeding and the like.

In order to solve the above-mentioned drawbacks, attempts have been made to put an organic phosphate compound having a large molecular weight into practical use as a flame retardant. For example, European Patent Application Publication No. 74
No. 60, tri (2,6-dimethylphenyl) phosphate compound, European Patent Application Publication No. 129824,
No. 129825, No. 135726, and British Patent Application Publication No. 2043083 show resorcinol.
Bisdiphenyl phosphate compounds, etc., US Pat. No. 468
Japanese Patent No. 3255 discloses a tribiphenyl phosphate compound. However, these phosphoric acid ester compounds must be used in a large amount for flame retardancy. In addition, according to our research and analysis, resin compositions flame-retarded by using these phosphoric acid ester compounds corrode the mold during molding, and during molding processing and molded products are used for a long time. During that time, the flame retardant is denatured, the molded product is discolored or blistered, and the electrical properties and flame retardant properties of the molded product deteriorate due to water absorption and the like.

As described above, conventionally, it has not been possible to provide a resin composition satisfying sufficient flame retardancy, performance required as a product, and stability at the same time.

[0006]

DISCLOSURE OF THE INVENTION The present invention provides a polyphenylene ether flame-retardant resin which is free from volatilization, smoke emission and bleeding of a flame retardant during molding and has excellent stability to withstand long-term use and recycling. It is intended to provide a composition.

[0007]

Means for Solving the Problems The present inventors have completed the present invention as a result of extensive studies to achieve the above-mentioned object. That is, the present invention provides (A) 100 parts by weight of polyphenylene ether resin, or 10 to 99 parts by weight of polyphenylene ether resin, and 90 to 90 parts of polystyrene resin.
With respect to 100 parts by weight as a total of 1 part by weight, (B) general formula (I),

[0008]

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(Here, R1 and R2 are methyl groups,
3 and R4 each independently represent a methyl group or hydrogen. n represents an integer of 1 or more. n1 and n2 each independently represent an integer of 0 to 2. ) Phosphoric acid ester compounds 0.1 to 3
A flame-retardant resin composition comprising 0 parts by weight and 0.01 to 7 parts by weight of a (C) metal oxide. The polyphenylene ether resin used in the present invention is represented by the following general formula (II-
1) and / or a homopolymer having a repeating unit represented by (II-2), or a copolymer.

[0010]

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(Here, R5, R6, R7, R8, R
9 and R10 independently represent an alkyl group having 1 to 4 carbon atoms, an aryl group, halogen, or hydrogen. However, R9 and R10 are not hydrogen at the same time. ) A typical example of a homopolymer of polyphenylene ether resin is poly (2,6-dimethyl-1,4-phenylene).
Ether, poly (2-methyl-6-ethyl-1,4-phenylene) ether, poly (2,6-diethyl-1,4)
-Phenylene) ether, poly (2-ethyl-6-n-)
Propyl-1,4-phenylene) ether, poly (2,
6-di-n-propyl-1,4-phenylene) ether, poly (2-methyl-6-n-butyl-1,4-phenylene) ether, poly (2-ethyl-6-isopropyl-1,4-) Examples thereof include phenylene) ether, poly (2-methyl-6-hydroxyethyl-1,4-phenylene) ether, and poly (2-methyl-6-chloroethyl-1,4-phenylene) ether.

Among these, poly (2,6-dimethyl-1,
4-phenylene) ether is particularly preferred. The polyphenylene ether copolymer is a copolymer having a phenylene ether structure as a main monomer unit. For example,
Copolymer of 2,6-dimethylphenol and 2,3,6-trimethylphenol, copolymer of 2,6-dimethylphenol and o-cresol, or 2,6-dimethylphenol and 2,3,6- Examples thereof include copolymers with trimethylphenol and o-cresol.

Further, in the polyphenylene ether resin of the present invention, various other phenylene ether units which have been proposed to be present in the polyphenylene ether resin can be used unless they are contrary to the gist of the present invention. It may be included as a partial structure. Japanese Patent Application No. 63-1 / 1988 discloses an example of a proposal for coexistence in a small amount.
2698 and JP-A-63-301222, 2- (dialkylaminomethyl) -6-methylphenylene ether units and 2- (N-alkyl-N-phenylaminomethyl) -6-methyl. Examples include a phenylene ether unit.

Further, a polyphenylene ether resin in which a small amount of diphenoquinone or the like is bound in the main chain is also included.
Furthermore, for example, polyphenylene ether modified with a compound having a carbon-carbon double bond, as described in JP-A-2-276823, JP-A-63-108059, JP-A-59-59724 and the like. Also includes.

The method for producing the polyphenylene ether resin used in the present invention is not particularly limited, but for example, it is described in US Pat. No. 4,788,277 (Japanese Patent Application No. 62-1987).
No. 77570), 2,6-xylenol can be produced by oxidative coupling polymerization in the presence of dibutylamine. Moreover, the molecular weight and the molecular weight distribution are not particularly limited.

The polystyrene resin used in the present invention is
A vinyl aromatic polymer and a rubber-modified vinyl aromatic polymer. Vinyl aromatic polymers include styrene, o
-Methylstyrene, p-methylstyrene, m-methylstyrene, 2,4-dimethylstyrene, ethylstyrene,
Polymers such as nuclear alkyl-substituted styrenes such as p-tert-butylstyrene, α-alkylsubstituted styrenes such as α-methylstyrene and α-methyl-p-methylstyrene,
And at least one of these one or more and other vinyl compounds
Examples thereof include copolymers with two or more kinds and copolymers with two or more kinds. Examples of the compound copolymerizable with the vinyl aromatic compound include methacrylic acid esters such as methyl methacrylate and ethyl methacrylate, unsaturated nitrile compounds such as acrylonitrile and methacrylonitrile, and acid anhydrides such as maleic anhydride. . Among these polymers, particularly preferred polymers are polystyrene and styrene-acrylonitrile copolymer (AS resin).

Examples of the rubber used for the rubber-modified vinyl aromatic polymer include polybutadiene, styrene-butadiene copolymer, polyisoprene, butadiene-isoprene copolymer, natural rubber and ethylene-propylene copolymer. You can In particular, polybutadiene and a styrene-butadiene copolymer are preferable, and as the rubber-modified aromatic polymer, rubber-modified polystyrene (HIPS),
Rubber-modified styrene-acrylonitrile copolymer (ABS
Resin) is preferred.

The phosphoric acid ester compound used as the component (B) of the present invention is represented by the general formula (I):

[0019]

[Chemical 4]

(Here, R1 and R2 are methyl groups,
3 and R4 each independently represent a methyl group or hydrogen. n represents an integer of 1 or more. n1 and n2 each independently represent an integer of 0 to 2. ). In the general formula (I), n1 and n2
Is 0 and R3 and R4 are preferably methyl groups.

In the general formula (I), n is an integer of 1 or more, and the heat resistance and workability differ depending on the number.
The preferred range of n is 1-10. The component (B) may be a mixture of n-mers. (B) of the present invention
The phosphoric acid ester compound as a component has a specific bifunctional phenol bond structure and a monofunctional phenol end structure.

As the bifunctional phenol, 2,2-bis (4-hydroxyphenyl) propane [commonly called bisphenol A], 2,2-bis (4-hydroxy-3-methylphenyl) propane, bis (4-hydroxyphenyl) is used. )
Examples include, but are not limited to, bisphenols such as methane, bis (4-hydroxy-3,5-dimethylphenyl) methane, 1,1-bis (4-hydroxyphenyl) ethane. Bisphenol A is particularly preferable.

The phosphoric acid ester compound as the component (B) is greatly suppressed in volatility and is excellent in stability and hydrolysis resistance. Further, it does not cause a problem such as gelation by causing a reaction with the polyphenylene ether resin, does not accelerate decomposition of the polyphenylene ether resin, and does not corrode metal parts such as a molding machine. .

The phosphoric acid ester compound as the component (B) can be obtained by reacting the above-mentioned bifunctional phenol and monofunctional phenol with phosphorus oxychloride, but the production method is not limited at all. The phosphoric acid ester as the component (B) is a phosphoric acid ester generally used within a range that does not impair the effects of the invention, for example, triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, cresyl diphenyl phosphate, dicresyl. It may contain phosphoric acid esters such as phenyl phosphate and hydroxyphenyl diphenyl phosphate, compounds obtained by modifying these with various substituents, and various condensation type phosphoric acid ester compounds.

Examples of the metal oxide used as the component (C) of the present invention include zinc oxide, magnesium oxide, cadmium oxide, antimony oxide, barium oxide, calcium oxide, titanium oxide, molybdenum oxide, and the like, and especially zinc oxide. , Magnesium oxide is preferred. As the metal sulfide that can be used as the component (D) of the present invention, zinc sulfide is preferable.

In the present invention, the flame retardancy of the composition is impaired by blending the polyphenylene ether resin composition with a specific bisphenol A / polyphosphate compound, a metal oxide, and optionally a metal sulfide. The stability of the resin such as hydrolysis resistance and thermal stability can be improved epoch-making. The resin composition of the present invention,
(A) 100 parts by weight of polyphenylene ether resin or 10 to 99 parts by weight of polyphenylene ether resin, and 90 to 1 parts by weight of polystyrene resin in total 10
0.1 to 30 parts by weight of the phosphoric acid ester compound as the component (B) and 0. 0 parts by weight of the metal oxide as the component (C) are used.
01 to 7 parts by weight and, if necessary, 0.01 to 7 parts by weight of the component (D) metal sulfide. (B)
If the blending ratio of the components is too small, the flame retardance is insufficient,
If it is too large, the heat resistance of the resin is impaired. If the blending ratio of the component (C) is too small, the stability improving effect is insufficient, and if it is too large, the mechanical properties and the like are impaired.

Other additives to the resin composition of the present invention, such as plasticizers, other flame retardants, antioxidants, stabilizers such as UV absorbers, release agents, etc., within the range not impairing the effects of the present invention. It is possible to add dyes and pigments, or fibrous reinforcing agents such as glass fibers and carbon fibers, and fillers such as glass beads, calcium carbonate and talc. The method for producing the resin composition of the present invention is not particularly limited, and can be kneaded and produced by using a kneader such as an extruder, a heating roll, a kneader, a Banbury mixer, or the like.

[0028]

EXAMPLES The present invention will be described in detail below with reference to examples, but the present invention is not limited to the following examples.
The phosphoric acid ester compounds used in Examples and Comparative Examples were as follows. (B-1): Bisphenol A-polyphenyl phosphate: Chemical formula (III) (mixture of n = 1 to 5)

[0029]

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(B-2): Resorcinol-polyphenyl phosphate: Chemical formula (IV) (n = 1 to 5 mixture)

[0031]

[Chemical 6]

(B-3): Triphenyl phosphate [manufactured by Daihachi Chemical Co., Ltd .: trade name TPP] The composition was evaluated by the following methods and conditions. Flame retardance: Based on UL standard 94 vertical combustion test method, the test was performed using a 1/8 inch test piece and ranked. Amount of smoke generated: The amount of smoke generated from the nozzle of the injection molding machine when purging the resin composition was visually observed.

Stability of composition: The water absorption rate of the test piece after the hydrolysis acceleration test was used as an index of stability. The hydrolysis acceleration test was carried out by exposing the test piece to 120 ° C. under 2 atmospheres of saturated steam for 300 hours.

[0034]

Example 1 Poly-2,6-dimethyl-1,4 having an intrinsic viscosity [η] of 0.52 measured at 30 ° C. in chloroform.
72 parts by weight of phenylene ether (hereinafter abbreviated as PPE), impact-resistant polystyrene resin (hereinafter abbreviated as HIPS) [Asahi Kasei Kogyo KK: Asahi Kasei Polystyrene 49
2] 14 parts by weight of polystyrene resin (hereinafter abbreviated as GPPS) [Asahi Kasei Kogyo KK: Asahi Kasei Polystyrene 6]
85] To 100 parts by weight of the resin composition of 14 parts by weight, 12 parts by weight of the phosphoric acid ester (b-1), 1.0 part by weight of zinc oxide, and octadecyl-3- (3-5-di- t
-Butyl-4-hydroxyphenyl) propionate (0.3 parts by weight) was mixed and melt-kneaded with a twin-screw extruder having a cylinder temperature of 300 ° C. to obtain pellets. The pellets were injection-molded and evaluated. The results are shown in Table 1.

[0035]

[Examples 2 and 3 and Comparative Examples 1 to 4] The components were mixed in the compositions shown in Table 1 and evaluated in the same manner as in Example 1. The results are shown in Table 1.

[0036]

[Table 1]

[0037]

EFFECTS OF THE INVENTION The polyphenylene ether flame retardant resin composition of the present invention is free from volatilization, smoke emission and bleeding of the flame retardant during molding and is used for a long period of time or recycled, as compared with the conventional flame retardant resin composition. It is possible to provide a flame-retardant resin composition that withstands heat and has excellent stability.

Claims (3)

[Claims] 1. A polyphenylene ether resin (A) 10
With respect to 0 part by weight, (B) general formula (I): (Here, R1 and R2 represent a methyl group, R3 and R4 independently represent a methyl group or hydrogen. N represents an integer of 1 or more.
n1 and n2 each independently represent an integer of 0 to 2. ) A polyphenylene ether flame-retardant resin composition comprising 0.1 to 30 parts by weight of a phosphate compound represented by the formula (4) and 0.01 to 7 parts by weight of a metal oxide (C). 2. A polyphenylene ether resin (A) 10
To 99 parts by weight and 90 to 1 parts by weight of polystyrene resin, a total of 100 parts by weight of (B) 0.1 to 30 parts by weight of the phosphate compound of the general formula (I), and (C).
A polyphenylene ether flame-retardant resin composition comprising 0.01 to 7 parts by weight of a metal oxide. 3. The polyphenylene ether flame-retardant resin composition according to claim 1, which further comprises (D) a metal sulfide in an amount of 0.01 to 7 parts by weight.